The 4 knob final version of the guitar pedal is a classic overdrive pedal that has been enhanced with a Baxandall tone control. This version is based on the Boss OD-1 Overdrive, Ibanez TS-808 Tubescreamer, and Boss SD-1 Super Overdrive pedals. The knobs on this pedal include a Drive knob, a Tone knob, a Bass knob, and a pre-tone lowpass filter toggle switch.

The Drive knob controls the gain of the pedal. The gain equation for this non-inverting amplifier is (Rf / Rg ) + 1, where Rf is the feedback resistor (the pot) and Rg is the resistor to ground. The Tone knob controls an EQ-style tone control that can provide boost or cut. The Bass knob is an addition to the original three-knob design, providing control over the lower frequencies. The pre-tone lowpass filter toggle switch offers options for the lowpass filter.

The Baxandall tone control in this version allows for a smoother pot feel with just a simple linear pot. This eliminates the need for an unusual S-taper pot that was used in the original Ibanez design to counteract the effect of 80% of the pot’s travel being bunched up in the middle doing not much. This version also drops the FET switching and buffers of the original designs, simplifying the signal path and optimizing it for true bypass switching.

Summary created by AI and may not be accurate. See original source.